Computers & Operations Research最新文献

{"title":"An exact branch-price-and-cut algorithm for the time-dependent cold chain pickup and delivery problem with incompatibility constraints","authors":"Hongyuan Luo ,&nbsp;Tao Ma ,&nbsp;Zhendong Li","doi":"10.1016/j.cor.2025.107007","DOIUrl":"10.1016/j.cor.2025.107007","url":null,"abstract":"<div><div>This paper addresses a cold chain transportation problem derived from a real-life situation, namely a time-dependent pickup and delivery problem with commodity incompatibility constraints (TDPDPI). In TDPDPI, the travel speed of these vehicles varies with the departure time, that is, the time-dependent travel speed. The quality delay cost of the perishable commodity also varies with the departure time, namely the time-dependent quality delay cost. The cost of this problem consists of two components: one is related to the total travel time, and the other is related to the quality delay cost of the perishable commodity. To solve TDPDPI, this paper develops an arc-based (mixed integer programming, MIP) model solved by CPLEX and a route-based (set-partitioning formulation, SPF) model. To address the SPF model, this paper proposes an exact branch-price-and-cut (BPC) algorithm. A specialized bidirectional labeling algorithm is developed to address the pricing problem. Additionally, subset row cuts (SRC) are employed as valid inequalities to enhance the quality of the lower bound in the SPF model. Extensive computational experiments are conducted to evaluate the efficacy of the proposed BPC algorithm. The results demonstrate that the BPC algorithm effectively solves the problem with 50 requests. Finally, this study conducts a sensitivity analysis of the key constraints and parameters of the model, providing valuable managerial insights.</div></div>","PeriodicalId":10542,"journal":{"name":"Computers & Operations Research","volume":"178 ","pages":"Article 107007"},"PeriodicalIF":4.1,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143395132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Edge downgrades in the maximal covering location problem","authors":"Marta Baldomero-Naranjo ,&nbsp;Jörg Kalcsics ,&nbsp;Antonio M. Rodríguez-Chía","doi":"10.1016/j.cor.2025.107003","DOIUrl":"10.1016/j.cor.2025.107003","url":null,"abstract":"<div><div>We tackle the downgrading maximal covering location problem within a network. In this problem, two actors with conflicting objectives are involved: (a) The location planner aims to determine the location of facilities to maximize the covered demand while anticipating that an attacker will attempt to reduce coverage by increasing the length of some edges (downgrade); (b) The attacker seeks to maximize the demand initially covered by the facilities but left uncovered after the downgrade. The attacker can increase the length of certain edges within a specified budget.</div><div>We introduce a mixed-integer linear bilevel program to formulate the problem, followed by a preprocessing phase and a matheuristic algorithm designed to address it. Additionally, computational results are presented to illustrate the potential and limitations of the proposed algorithm.</div></div>","PeriodicalId":10542,"journal":{"name":"Computers & Operations Research","volume":"178 ","pages":"Article 107003"},"PeriodicalIF":4.1,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143420802","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Benefit Maximizing Network Design in the public sector","authors":"Robert Aboolian,&nbsp;Majid Karimi","doi":"10.1016/j.cor.2025.107004","DOIUrl":"10.1016/j.cor.2025.107004","url":null,"abstract":"<div><div>This paper introduces the Benefit Maximization Network Design Problem (BNDP), an innovative framework aimed at optimizing public service systems. By integrating consumer choice models with a focus on minimizing consumer disutility, the BNDP strategically maximizes societal welfare by optimizing the net benefits derived from service utilization, carefully weighing the costs of service capacity against the value delivered to the public. An essential aspect of this study is the development of an <span><math><mi>ϵ</mi></math></span>-optimal solution approach, which effectively addresses the intricate optimization challenges inherent in public service system design, including nonlinear equilibrium conditions. This approach efficiently identifies the optimal number, locations, and capacities for service facilities, ensuring practical and effective solutions despite the model’s complexity. A practical application of the BNDP is demonstrated through a detailed case study on preventive healthcare in San Diego, showcasing the model’s ability to refine operational solutions and significantly enhance societal benefits. The results underscore the importance of prioritizing benefit maximization over simplistic capacity thresholds and participation maximization, leading to either higher levels of consumer participation while using optimal levels of resources or comparable levels of customer participation with significantly fewer resources and reasonable utilization rates. Furthermore, the paper explores the model’s applicability in the private sector to maximize corporate profits, highlighting its versatility. The study concludes by advocating for policymakers to prioritize the use of BNDP in establishing optimal budgets for public agencies rather than allocating resources based on exogenous capacities.</div></div>","PeriodicalId":10542,"journal":{"name":"Computers & Operations Research","volume":"178 ","pages":"Article 107004"},"PeriodicalIF":4.1,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143388317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The drone-assisted simultaneous pickup and delivery problem with time windows","authors":"Xia Zhang,&nbsp;Shuang Zeng","doi":"10.1016/j.cor.2025.106996","DOIUrl":"10.1016/j.cor.2025.106996","url":null,"abstract":"<div><div>The explosion of e-commerce has led to a continued increase in CO₂ emissions in logistics. In this article, we explore the role of collaboration between drones and trucks in logistics in mitigating environmental pollution. We propose a mathematical model of drone-assisted truck service that considers customers’ simultaneous pickup and delivery needs within a specific time window. We name it the drone-assisted truck simultaneous pickup and delivery problem considering time windows (DASPDPTW), the objective is to minimize the total CO₂ emissions. The energy consumption of the drone is calculated based on a load-based energy model. We design an improved adaptive large neighborhood search (IALNS) algorithm to solve large instances, which contains some special operators for the DASPDPTW. Numerical experiments have verified the effectiveness of IALNS, and drone-assisted trucks can effectively alleviate environmental pollution. Logistics companies can consider incorporating drones into delivery systems to promote supply chain sustainability.</div></div>","PeriodicalId":10542,"journal":{"name":"Computers & Operations Research","volume":"178 ","pages":"Article 106996"},"PeriodicalIF":4.1,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143395131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Routing and driver break scheduling with working and driving regulations: A flexible approach for various general pickup and delivery problem variants","authors":"Ning Xue,&nbsp;Huan Jin,&nbsp;Tianxiang Cui","doi":"10.1016/j.cor.2025.107001","DOIUrl":"10.1016/j.cor.2025.107001","url":null,"abstract":"<div><div>This paper provides a solution to the driver break scheduling problem that can be integrated into current solvers for the generalised pick-up and delivery problem (GPDP) with a negligible increase in development costs. The driver break scheduling problem affects truck drivers who are required to adhere to working time and/or driving time regulations that oblige them to take mandatory breaks. These regulations are in force in many countries across the European Union, Great Britain, Australia, New Zealand, and the United States. We propose a flexible solution strategy that combines routing with driver break scheduling, taking into account both Regulations (EC)561/2006 and 2002/15/EC within a single day of operation. We deliberately incorporate driver breaks into the routes generated, with the aim of minimising route duration. The method proposed in this paper is particularly beneficial for the solvers that have not initially implemented driver break rules but need to introduce this functionality to accommodate customers, given the critical nature of driver break rules for effective scheduling. This is a flexible approach because the method proposed here can be applied directly to any individual route and at any stage of the scheduling process. For instance, it can be used during the constructive heuristic or the improvement heuristic phases. It is also applicable at the column generation stage of an exact method after a route has been constructed. This method is particularly beneficial when a human scheduler wishes to make manual adjustments along a single route, such as adding or removing an order from the route. Experimental analyses, grounded in two benchmark instances, affirm the efficacy of the proposed method. Results indicate that the method yields a 6.1% decrease in distance, a 1.7% reduction in duty time, and a 1.1% decrease in the number of unassigned tasks when contrasted with the standard compliant approach. We also offer guidance on how to tailor this method for driver break scheduling in accordance with the regulatory standards of Australia and New Zealand.</div></div>","PeriodicalId":10542,"journal":{"name":"Computers & Operations Research","volume":"177 ","pages":"Article 107001"},"PeriodicalIF":4.1,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143348684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimization of passenger flow control and customized bus bridging in urban rail transit network","authors":"Qingqing Zhao ,&nbsp;Jinjin Tang ,&nbsp;Chao Li ,&nbsp;Qiuhan Dong ,&nbsp;Tao Feng ,&nbsp;Xingwei Yang","doi":"10.1016/j.cor.2025.106997","DOIUrl":"10.1016/j.cor.2025.106997","url":null,"abstract":"<div><div>When dealing with large passenger flows in urban rail transit, developing reasonable passenger flow control plans is a crucial aspect of operational management. When many passengers wait outside the stations, customized buses can serve as an effective way to alleviate passenger pressure. To obtain reasonable passenger flow control and customized bus connection plans, we propose an optimization method for passenger flow control and customized bus connections. Firstly, we construct a two-stage model. The first-stage model formulates the passenger flow control plan to minimize the number of waiting passengers inside and outside the station considering factors such as passenger arrivals and urban rail transit train departures and arrivals. The second-stage model develops the customized bus plan based on a time–space-state network. According to the characteristics of the model, the CPLEX solver is used to solve the first-stage model, and a Lagrange relaxation-based solution method is designed to solve the second-stage model. To verify the effectiveness of the model, a small-scale case study including two lines and five stations is designed, and the results show that the proposed method can achieve effective passenger flow control and bus connection plans. Additionally, actual data from the Chengdu Metro is used to further validate the feasibility of the method. The results indicate that the passenger flow control and bus bridging plans can effectively reduce passenger waiting time. The proposed method can effectively alleviate passenger pressure, ensure passenger travel safety, and further promote the coordinated development of public transportation.</div></div>","PeriodicalId":10542,"journal":{"name":"Computers & Operations Research","volume":"178 ","pages":"Article 106997"},"PeriodicalIF":4.1,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143420804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-neighborhood simulated annealing for the oven scheduling problem","authors":"Francesca Da Ros ,&nbsp;Luca Di Gaspero ,&nbsp;Marie-Louise Lackner ,&nbsp;Nysret Musliu ,&nbsp;Felix Winter","doi":"10.1016/j.cor.2025.106999","DOIUrl":"10.1016/j.cor.2025.106999","url":null,"abstract":"<div><div>The Oven Scheduling Problem (OSP) is an NP-hard real-world parallel batch scheduling problem that arises in the semiconductor manufacturing sector. It aims to group compatible jobs in batches and to find an optimal schedule in order to reduce oven runtime, setup costs, and job tardiness. This work proposes a Simulated Annealing (SA) algorithm for the OSP, encompassing a unique combination of four neighborhoods and a construction heuristic as initial solution. An extensive experimental evaluation is performed, benchmarking the proposed SA algorithm against state-of-the-art methods. The results show that this approach consistently finds new upper bounds for large instances, while for smaller instances, it achieves solutions of comparable quality to state-of-the-art methods. These results are delivered in significantly less time than the literature approaches require. Additionally, the SA is extended to tackle a related batch scheduling problem from the literature. Even in this case, the algorithm confirms its effectiveness and robustness across different problem formulations by improving results for many instances.</div></div>","PeriodicalId":10542,"journal":{"name":"Computers & Operations Research","volume":"177 ","pages":"Article 106999"},"PeriodicalIF":4.1,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143348683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Knowledge graph based question-answering model with subgraph retrieval optimization","authors":"Rui Zhu ,&nbsp;Bo Liu ,&nbsp;Qiuyu Tian ,&nbsp;Ruwen Zhang ,&nbsp;Shengxiang Zhang ,&nbsp;Yanna Hu ,&nbsp;Jiuxin Cao","doi":"10.1016/j.cor.2025.106995","DOIUrl":"10.1016/j.cor.2025.106995","url":null,"abstract":"<div><div>Knowledge graph-based question answering (QA) is a critical domain within natural language processing, aimed at delivering precise and efficient responses to user queries. Current research predominantly focuses on minimizing subgraph sizes to enhance the efficiency and compactness of the search space. However, natural language queries often exhibit ambiguities, and merely reducing subgraph sizes may overlook relevant answer entities. Additionally, redundant relationships among entities in the knowledge graph can adversely affect QA model performance. To address these limitations, this paper introduces a novel QA model that optimizes subgraph retrieval. The proposed model enhances entity linking and subgraph retrieval by leveraging contextual features from both questions and entities. It disambiguates entities using relevant contextual features and refines the search process through entity relation merging and entity ranking strategies. This methodology improves entity recognition and linking, reduces subgraph dimensions, and broadens answer coverage, resulting in substantial improvements in QA performance. Experimental results on the CCKS2019-CKBQA dataset demonstrate the modelś effectiveness, showing an average F1 score improvement of 2.99% over the leading baseline model. Furthermore, the model’s application in the field of ocean engineering underscores its practical utility and significance.</div></div>","PeriodicalId":10542,"journal":{"name":"Computers & Operations Research","volume":"177 ","pages":"Article 106995"},"PeriodicalIF":4.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143132610","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improved A* algorithm incorporating RRT* thought: A path planning algorithm for AGV in digitalised workshops","authors":"Na Liu,&nbsp;Zihang Hu,&nbsp;Min Wei,&nbsp;Pengfei Guo,&nbsp;Shuhan Zhang,&nbsp;Aodi Zhang","doi":"10.1016/j.cor.2025.106993","DOIUrl":"10.1016/j.cor.2025.106993","url":null,"abstract":"<div><div>The implementation of efficient path planning algorithms can facilitate enhanced transport efficiency in AGVs (Automated Guided Vehicles). However, the current path planning algorithms used in the workshop can determine the shortest path, but there are problems such as low search efficiency, long search time, and many path inflection points. Such issues have the potential to negatively impact the transport efficiency of the AGV, rendering them unsuitable for actual workshop conditions. This paper proposes a new algorithm, named IA-RRT* (Improved A* Algorithm Integrating RRT* Thought), for path planning of AGV in digitalised workshops. The algorithm modifies the cost evaluation function of the A* algorithm to provide a less strong direction for the search, narrowing the search scope and preventing the algorithm from converging too quickly and getting stuck in a local optimal path. Meanwhile, the IA-RRT* algorithm combines the randomness concept of the RRT* algorithm with an inflection point penalty term. The objective is to find a path with fewer inflection points, making it more practical for production. Simulation experiments have shown that the IA-RRT* algorithm outperforms several other path planning algorithms in terms of path length cost, algorithm calculation time, and number of inflection points. The paths generated by the IA-RRT* algorithm are applicable to the working situation of AGV and have practical significance.</div></div>","PeriodicalId":10542,"journal":{"name":"Computers & Operations Research","volume":"177 ","pages":"Article 106993"},"PeriodicalIF":4.1,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143348681","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A branch-and-cut-and-price algorithm for shared mobility considering customer satisfaction","authors":"Min Xu","doi":"10.1016/j.cor.2025.106998","DOIUrl":"10.1016/j.cor.2025.106998","url":null,"abstract":"<div><div>This study determines the exact optimal fleet size, ride-matching patterns, and vehicle routes for shared mobility services (SMS) that maximize the profit of service operators considering ride-pooling and customer satisfaction. We make the first attempt to consider a nonlinear multivariate customer satisfaction function with respect to the features of the riders and the system under a ‘two riders-single vehicle’ ride-pooling scenario in a special case of dial-a-ride problem (DARP). A set packing model and a tailored branch-and-cut-and-price (BCP) approach are proposed to find the exact optimal solution of the problem. Unlike existing exact solution methods for DARP, we exploit the characteristic of the ride-pooling scenario and decompose the ride matching and vehicle routing in an effective two-phase method to solve the pricing problem of the BCP approach. Particularly, in Phase 1, feasible matching patterns subject to practical constraints are identified. In Phase 2, a heuristic and an exact label-correcting method with a bounded bi-directional search are sequentially employed to solve a new variant of elementary shortest path problem with time window (ESPPTW) in a network constructed upon rides and feasible ride matching patterns identified in Phase 1. The labeling methods are further accelerated by a strengthened dominance test, the aggregate extension to other depots, and the decremental search space. Valid inequalities are also incorporated to further improve the upper bound. The proposed solution method is evaluated in randomly generated instances and the instances created from the real mobility data of Didi. Managerial insights are generated through impact analysis.</div></div>","PeriodicalId":10542,"journal":{"name":"Computers & Operations Research","volume":"177 ","pages":"Article 106998"},"PeriodicalIF":4.1,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143132609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}